1. Field of the Invention
The present invention relates to a developer supply system and an image forming apparatus incorporating same, and more particularly, to a developer supply system that supplies an electrophotographic developer formed of a mixture of toner and carrier particles, and an image forming apparatus incorporating such a developer supply system.
2. Discussion of the Background
Electrophotographic image forming apparatuses, such as photocopiers, printers, facsimiles, or the like, have development devices in which an electrostatic latent image formed on a photoconductor drum or belt according to image data is rendered visible using developer particles. A common form of such development process uses a two-component developer formed of a mixture of toner and carrier particles that form a “magnetic brush” to transfer toner to a photoconductive surface. Due to its high toner transfer rate, reproducibility of halftone images, and immunity to effects of temperature and/or humidity variations, magnetic brush development has become prevalent in modern electrophotographic apparatuses.
A magnetic brush development device typically incorporates a developer supply system that continuously supplies new toner as the two-component developer becomes depleted of toner during repeated imaging cycles. The developer supply system holds new toner in a replaceable container or cartridge, such as a plastic bottle or a deformable bag formed of flexible material, which is detachably mounted on the printer to establish fluid communication with the development unit.
Currently, some toner cartridges feature automatic identification technologies to enable a printer to identify characteristic of a cartridge or toner in use. Such a cartridge has an embedded data carrier or memory, e.g., a radio frequency identification (RFID) chip, so that a host device or printer can retrieve various types of identification data, such as type of compatible printer, date of manufacture, color of toner, or remaining amount of toner, etc., by establishing electrical contact with the memory. Such identification capability allows ready management of printers employing two-component developer, and will likely be widely adopted in future products and systems related to electrophotography. In this regard, various techniques have been proposed to provide a developer container with identification capability.
For example, one conventional technique provides a “bag-in-box” toner cartridge with an identification data carrier. This cartridge is formed of a flexible bag accommodating toner and a rigid enclosure box surrounding the flexible bag, and the data carrier is attached to the enclosure box. The technique is designed for use in a host device having a data reader built in a holder for holding the enclosure box. When properly installed and positioned, the cartridge can exchange information with the host device through electrical connection established between the data carrier and reader.
Another conventional technique proposes a toner container formed of a flexible toner bag without an enclosure box, which has a data carrier attached to a fitting defining an exit port for connection to an image forming apparatus. Compared to the bag-in-box container, the toner bag without enclosure allows for easy recycling or disposal when empty. According to this method, providing the data carrier on the fitting efficiently holds it in position relative to the image forming apparatus, where the fitting is securely connected to the apparatus body to provide fluid communication between the cartridge and the image forming apparatus. However, such a technique has a drawback in that the data carrier located adjacent to the exit port is susceptible to contamination from particles leaking around the fitting, making it difficult to provide a reliable electrical connection between the data carrier and reader in the developer supply system.